Additional Study Information: If so, you may be able to take part in a clinical research study. This study is being done to see how wellcarbon dioxide (CO2) may provide relief from the pain associated with Trigeminal Neuralgia (TN). CO2 is a gas that is part of the air we breathe and is used to make bubbles in carbonated drinks. The screening and treatment office visit can be done in the same day. Follow-up will be completed by telephone.